![Conexant Fusion 878A Manual Download Page 141](http://html.mh-extra.com/html/conexant/fusion-878a/fusion-878a_manual_2652146141.webp)
Fusion 878A
5.0 Control Register Definitions-Function 0
PCI Video Decoder
5.3 Local Registers (Memory Mapped)
100600B
Conexant
5-23
0x068—ADC Interface Register (ADC)
Upon reset, ADC is initialized to 0x82. CRUSH is the LSB.
Bits
Type
Default
Name
Description
[7:6]
10
[5]
Reserved
This bit is reserved and must be set to 0.
[4]
RW
0
AGC_EN
This bit controls the AGC function. If this bit is disabled, REFOUT is not driven
and an external reference voltage must be provided. If this bit is enabled,
REFOUT is driven to control the A/D reference voltage.
0 = AGC enabled
1 = AGC disabled
[3]
RW
0
CLK_SLEEP
When this bit is at a logical 1, the decoder clock is powered down, but the
device registers are still accessible. Recovery time is approximately 1 s to
return to capturing video.
0 = Normal clock operation
1 = Shut down the system clock (power down)
[2]
RW
0
Y_SLEEP
This bit enables putting the luma ADC in sleep mode.
0 = Normal Y ADC operation
1 = Sleep Y ADC operation
[1]
RW
1
C_SLEEP
This bit enables putting the chroma ADC in sleep mode.
0 = Normal C ADC operation
1 = Sleep C ADC operation
[0]
RW
0
When the CRUSH bit is high (adaptive AGC), the gain control mechanism
monitors the A/Ds for overflow conditions. If an overflow is detected, the
REFOUT voltage is increased, which increases the input voltage range on the
A/Ds.
0 = Non-adaptive AGC
1 = Adaptive AGC